I am in need and I hate to publicly admit I don't know the answer to this basic question. I have been replacing various components on my car since I bought it 2 months ago and I am confused. While I was replacing the rear diffy bearings and drive axels I decided to change the tranny filter and fluid, in both the tranny and converter. I drained and replaced the filter and began filling the tranny with new fluid. My Haynes manual calls for 6.9 qts. fluid with converter drain. I put 6 in and ran the car at idle for approximately 20 minutes, rear end was not yet completed. After 20 minutes I checked and dipstick showed low. I put another .75 qts. in which seemed reasonable and ran another 15 minutes and level was correct. I then 3 days later drove the car about 45 minutes and stopped and checked the fluid level, car still idling, and I was about a quart too much. What gives? Does one bring the tranny up to normal temp and while engine idles check the level? I do not understand what happened. Can some one help me with this one? Thank you in advance.

Rick


1982 300D Turbo
1966 TR4A
1966 TR4A

Yep, I never had a car where measuring the trans fluid level was sooo temperature sensitive. Sounds like you are probably overfilled, but maybe not by as much as you think. When I get in that situation, I siphon about a pint at a time, then recheck with engine idling about 3 minutes after at least a 30 minute run. Eventually, you will get it where you want it, but it can take a couple of attempts. Somewhere, I remember reading an article, probably in an old Star Magazine, of how to measure it cold. If I ever run across that one again, I will post the info.

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Thank you Paul. I was begining to think I was an idiot cause I could not figure out what was changing the level so much. I will check it in the morning.

Rick

I read that check while cold post and I think it was in the pro tech section about a week ago ,and it said the level was read with tranny cold but ideling in park and the level should be 10 mm below one of the lines but I can't remember which one (big help huh!) but maybe that will help for a search.........
William Rogers......

From a response to an earlier post of mine:
As usual, you take all of the risk yourself, but personally, I am more than willing to believe Randy after reviewing his impressive credentials. Thanks Randy!

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VR
1967 250SL

Thank you very much all. I will scribe a mark at 10mm and then I can check it anytime.

Rick

...just to be certain, the cold reading of 10mm below the lowest line means "cold and idling"? Or just cold like an oil check?


thanks to all.



also... do you folks get this annoying looking dipstick reading which to me appears to be mostly fluid in the tube streaking upwards? I've checked it 100 times and never once had a normal straight line reading (as with oil).

picture will not display so here is a link

feel free to make fun of my frustrated ignorance. I do it all the time.

Engine running and in park to read the fluid level.

And remember to cycle the transmission (while standing with brakes applied) R - N - D and back several times, to ensure the fluid gets distributed to all the actuators inside the transmission.

The later 722.6 transmissions are even more sensitive, you have to be at 80C exactly for the dipstick tool (yes, there is a tool, the dipstick pipe has a sealed cap and no stick!) to be accurate.

The newest transmissions don't even have a stick tube, you have to fill it from below and let it dribble to the spillover level in the fill pipe again at exactly 80C.

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i have a hard time getting a good read on the dipstick, so I now do it like so: make sure engine is running and temp is 80c. Pull the dipstick out and leave it out for a few minutes. Then dip it in and check it. That seems to give me a better reading.

Yeah reading A/T fluid can be tricky, when the stuff is brand new and clean it can be really hard to see on the stick, and any fluid on the tube walls can monkey with the reading. I do it the same way you do, still seems like I need a flash light every time to make sure I can see the cutoff of where the fluid level is.

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1995 E300 Diesel
~300k

thanks!

The way I check mine which is a 722.3 version, from cold, I start and let run for about a minute, shut it off and then check a couple of times, from what I have gathered is it's supposed to be 10 mm below lower mark. In a perfect world the temp would be 77 F. After driving awhile and the fluid at normal operating temp the dipstick shows the correct level the top line. In the beginning I over-filled and siphoned off a lot.

I flipping hate checking the level on these, so it's nice to see a few tips I can try. All I ever seem to get is a smear and if I have to add any then forget about checking it again because now there's a bunch coating the inside of the tube...

-Rog

the dead cold level check on a 722.3 is 7mm from the lower part of the hashmark.

The 722.4 are kept 11mm below the lower mark.

after doing this practice I always have the perfect level showing up when the transmission is hot.


in my 722.6 its similar - I fill till its 25C mark and drive, then recheck it when hot - I use a thermistor in a hose which I push down the tube - it takes the fluid temp reading directly. Its usually at correct level.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
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Zulfigar, can you tell us more about the thermistor in a hose? Is this something that can be purchased or did you contruct it yourself? Sounds like a handy device to have around.

I too rely on getting as base reading at 25C on my 722.4 and 722.6.

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